Demand type oxygen valve



Oct. 4, 1966 J. c. MATCHETT 3,276,462

DEMAND TYPE OXYGEN VALVE Filed NOV. 26, 1962 INVENTOR.. ./A//V 6. A447095?? United States Patent O 3,276,462 DEMAND TYPE OXYGEN VALVE John C. Matchett, 6613 Glorywhite, Lakewood, Calif. Filed Nov. 26, 1962, Ser. No. 239,955 9 Claims. (Cl. 137-64) The present invention relates generally to oxygen therapy equipment and more particularly to a demand type valve regulating the iiow of oxygen or other gas to a mask or the like in response to the breathing requirements of a person using the mask.

The present type of valve is known as a demand type valve as opposed to a constant How valve or a valve such as is used in a resuscitator. In a constant ow system the oxygen mask is constantly iiooded with oxygen or other gas being administered from a suitable source and under a slight pressure, some systems also including a Ibreathing bag which serves as an intermediate reser- Voir. Systems of this constant flow type have the disadvantage that the oxygen is flowing constantly and, therefore, much of it is wasted. Probably less than half of the oxygen is actually inhaled and thereby used, the rest being wasted to the atmosphere through the exhaust valve in the mask. This is necessarily costly. Also, the user must exhale against the incoming positive pressure of the oxygen. This may be objectionable to the user when weak, since constant breathing against a pressure, even though slight, becomes very tiring.

The resuscitator apparatus Ibears little resemblance to the present invention because it forces oxygen into the lungs under a precise pressure and then draws the air out of the lungs as a result of the operation of mechanical means over a fixed cycle. There is in this case no response to the normal breathing of the user.

A demand type system for supplying oxygen to a user has several advantages. In the iirst place, the wasted oxygen is reduced to a minimum because substantially all of the oxygen supplied to the mask is inhaled and thus passes into the lungs before being exhausted to the atmosphere.

Another advantage is that the user ydoes not have to exhale `against an existing pressure. Thus, the use of the mask imposes no appreciable burden upon a patient and a substantially normal breathing cycle is possible. Also, the user does not reinhale a large portion of his own breath with each cycle, because the interior volume of the mask is not as large as in the case of a constant flow mask or a system having a breathing bag as a reservoir.

A further advantage of the demand type system is that a face mask can be applied and used instantly without the necessity of having to turn valves on and adjust flow controls. This greatly simplifies the operation of the system in the hands of an unskilled user or attendent.

The critical component of the demand type system of supplying oxygen is the Valve. The characteristics of the demand type valve make the system distinctive and satisfactory operation of the system depends entirely upon the proper functioning of the valve. In spite of the advantages of the demand type system, there are relatively few demand type valves available for users. many of them are relatively costly Ibecause of their complex structure and, therefore, are sometimes diicult to operate properly and generally in need of costly adjustment to maintain them in proper operating condition. The ordinary unskilled user or attendent not trained in the use of these valves would be unable to use them satisfactorily.

Thus it is a general object of the present invention to provide a demand type valve of novel design which is 3,276,462 Patented ct. 4, 1966 greatly simplified in its construction and is therefore inexpensive to manufacture.

It is also an object of the invention to provide a demand type valve which is simple in operation so that unskilled `and untrained people can use the valve Without difhculty and without the necessity of constant adjustment or maintenance operations on the valve to keep it in operating condition.

A further object of the invention is to provide a deman-d type valve which is lightweight in construction and therefore is easily moved to open position and back to closed position in which latter position it securely closes the inlet port, the movements requiring such little force that the valve is extremely sensitive to the breathing demand of the user.

These objects of the invention have been achieved in a demand type oxygen valve -by providing a housing having an interior space, a iiexible diaphragm within the housing which forms in cooperation with the housing a chamber of which one wall is the diaphragm, the diaphragm being exposed at one side to iiuid pressure in the chamber and at the other side to atmospheric pressure and yielding to the pressure of the fluid media at opposite sides thereof, means for introducing a gas under pressure into the chamber including a discharge port opening into the chamber, means providing a passage from the chamber to the user of the regulator, a movable valve member which is normally biased to a position closing said port to prevent entry of gas into the cham-ber, and means periodically coupling the valve means to the diaphragm and movable thereby to move the valve means in opposition to the biasing means to a position opening said port in response to fluid pressure exerted on the diaphragm.

Other .objects and advantages of the invention will be hereinafter ydescribed or will become apparent to those skilled in the art, and the novel features of the invention will be defined in the appended claims.

Referring to the drawings:

FIG. 1 is a schematic view of a demand type oxygen supply system in which is incorporated a demand type valve construction according to the present invention;

FIG. 2 is a median longitudinal section through the demand type valve of the present invention, with the valve in closed position;

FIG. 3 is a section similar to FIG. 2 showing the valve is open position;

FIG. 4 is a transverse section on line 4-4 of FIG. 3;

FIG. 5 is a fragmentary transverse section on line 5 5 of FIG. 2; and

FIG. 6 is an enlarged fragment of FIG. 3 showing especially the discharge port and the movable Valve member in open position.

Referring now to the drawing, and especially to FIGS. 1 and 2, it will be seen that the demand type valve of the present invention is indicated generally at 10. It is shown in FIG. 1 in a complete oxygen supply system in which oxygen is supplied to the valve through a hose or tubing 11 connected to the inlet side of the valve and also to any suitable source of gas under pressure, such as tank 12. Gas is held in the tank under a relatively high pressure, norm-ally reaching values as high as 2000 p.s.i., the pressure at the outlet from the tank Ibeing reduced by a reducing valve 14 to a substantially lower pressure, normally under 50 p.s.i. and usually in the neighborhood of 25-30 p.s.i. It will be realized that the source of oxygen or other gas is not limitative upon the present invention as it is common practice nowadays for hospitals to be piped with gas supply systems having outlets at bedside, with which valve 10 maybe used.

In FIG. 1 the demand valve is shown as being mounted directly upon face mask which has an exhaust valve 16 of any suitable type. The construction of the mask and its exhaust valve are not described herein, since they constitute no part of the present invention and various products for this purpose are widely known.

.From FIG. 2 it will be seen that the demand valve 1th comprises a housing 20 of circular Ioutline (FIG. 4) made in two parts 21 and 22. The two parts of the housing are preferably molded from some lightweight material, for example a synthetic resin or plastic, and they define between them an interior space.

Located within housing 20 is a llexible diaphragm 23 which typically and preferably is Iconfined around its entire periphery by being clamped between the two housing sections 21 and 22 to hold the diaphragm in place. It will thus be seen from reference to FIGS. 2 and 3 that the diaphragm in cooperation with the housing, and more especially that portion of the housing represented by housing section 21, forms an interior chamber 24 one side of which is the flexible diaphragm. The diaphragm is thus exposed fully at one side to the pressure of the fluid medium in chamber 14. A plurality of openings 25 in housing section 22 expose the other side of the diaphragm to the pressure of the atmosphere. The diaphragm is very thin and flexible so that it yields easily to pressures of fluid media at the opposite sides of the diaphragm.

At one side of the housing is collar 26 which is hollow and serves as means providing a passage from chamber 24 to the user of the regulator. The internal passage through collar 26 is preferably of substantial diameter in order to minimize resistance to air flow through it and also of a size to t around a projection on mask 15 so that valve 10 can be mounted directly onto mask 15 in communication with the interior of the mask.

The means for introducing the oxygen or any other gas under pressure into chamber 24 takes the form of a hollow, rigid core mem-ber 30`havting a longitudinally extending passage 31. The inner end of passage 31 is closed except for the discharge port to be described. The outer end of passage 31 is open to receive oxygen or other gas when hose 11 is attached to the projecting end of the core 30. Core 30 is a press fit in the wall of the housing provided by housing section 22.

It will be noted that internally of the housing core 30 is provided with an annular shoulder 32, shown particularly in FIG. 6. This shoulder around the core engages diaphragm 23 on the inner face thereof, that is, the face exposed to chamber 24, and contines the diaphragm centrally between shoulder 32 and the opposing portion of housing 2t). Thus, core 30 extends through d-iaphragm 23 centrally thereof to terminate inside the housing, preferably within chamber 24, and the core provides a gas passage from the exterior of the demand valve to the interior chamber 24.

As will be seen from FIG. 6 particularly, the outside surface of the terminal section of core 30 is tapered or frusto-conical in shape. In this tapered portion of the core there are two oppositely disposed, radially extending slots 34 which cut thro-ugh the wall of the core and pr-ovide a pair of gas discharge ports 34 communicating between passage 31 inside the core and chamber 24 inside the housing. When ports 34 are open as in FIGS. 3 and 6, gas lcan flow freely from passage 31 through ports 34 into the housing chamber and thence out through passage 27 in collar 26 to mask 15.

To shut off the flow of oxygen when there is no demand `for it, movable valve member 36 is provided which is movable to a position covering ports y34 in order to close them to the discharge of gas, as indicated in FIG. 2. Valve member 36 is annular in configuration and the inner wall of the central opening is tapered to conform to the taper of the terminal section of core 30. Thus, there is a wedging effect as the valve member moves toward the larger diameter of the tapered section of the core member which causes the valve member to stop at a proper position to cover ports 34 and to tightly engage the exterior surface of the core in order to prevent leakage of gas through the ports.

Valve member 36 is normally biased to the closed position of FIG. 2 by a very lightweight spring 38 which bears at Ione end against the valve member and at the other end against a suitable xed abutment. In this embodiment of the invention, this abutment is provided by a lock ring 40 in passage 27. The construction of the lock ring is shown in detail in FIG. 5 from which it will be seen that ring 40 comprises an annular member with a plurality of radially extending tabs which engage the wall of passage 27 and anchor the ring in place. It is preferred to use two such rings in the passage to hold between them screen filter 41. Any other suitable -abutment means, for example `an annular shoulder on the housing, may be employed if desired.

In order to move the valve member 36 to a position in which discharge ports 34 are uncovered, means are provided for periodically coupling the valve means to the diaphragm. Such coupling means operates to move the valve member to the open position in response to user demand which causes a drop in pressure in chamber 24 that in turn causes movement of diaphragm 23 away from housing section 22 and in a direction to reduce the volume of chamber 24. The coupling means comprises disc shaped pressure plate 45 mounted upon Iand movable with the movable valve member 36. As shown in FIGS. 3 and 4, when certain pressure conditions exist in the fluid media surrounding diaphragm 23, the diaphragm engages pressure plate 45 and moves it from the position of FIG. l to the position of FIG. 3 in opposition to the force exerted by spring 38. This movement of pressure plate 45 carries with it valve member 36 which is thereby moved from the closed position to the open position in which ports 34 are uncovered.

Pressure plate 45 has a gas pervious central section 45a through which gas issuing from ports 34 can ow to enter the valve chamber 24. A simple and preferred manner of providing a perforate or gas pervious central section for the plate is Ito make the entire plate of a wire cloth screen or similar material, although it will be realized that the invention is not necessarily limited thereto since other constructions may be employed to permit gas ow through the central section 45a which immediately surrounds valve member 36.

As clearly shown in the drawings, the central section 45a of the pressure plate is lconcave on the side facing the diaphragm so that contact between the diaphragm and the pressure plate is prevented over the central area. This construction is provided Isince gas ports 34 are loca-ted between the diaphragm and the pressure plate when the valve is in the open position and this construction makes it possible for the gas to escape from the space 46 between the diaphragm and pressure plate and mmediately surrounding core 30 by passing through the pressure plate into lchamber 24. From chamber 24 the gas leaves through passage 27 to enter mask 15.

Having described the construction of my improved demand type oxygen valve, its operation will now be reviewed briefly. The valve is normally closed with lthe parts in the position as shown in FIG. 2. Annular valve member 36 covers ports 34, being moved to this position under the pressure exerted by spring 38. Diaphragm 23 is not normally in engagement with pressure plate 45.

When the patient inhales, the pressure within mask 15 drops below atmospheric. This pressure drop is communicated quickly through passage 27 to valve chamber 24. Diaphragm 23 is very highly sensitive to a pressure differenti-al in the uid media at the two sides of the diaphragm, Iand the pressure in chamber 24 being lower than atmospheric causes the atmospheric pressure entering through openings 25 in the housing wall to move the diaphragm to the right as viewed in the figure.

This movement of the diaphragm causes it to engage pressure plate 45 and carry the pressure plate to the right, moving valve member 36 away from ports 34, as shown in FIG. 3. Oxygen or other gas can now leave core 30 through ports 34, as previously described and reaches the patient through passage 27. As long as the user inhales, there is maintained a pressure differential on the diaphragm that holds it in the position of FIG. 3 with port 34 open.

Upon exhaling, the pressure within mask land also chamber 24 normally becomes higher than atmospheric. The fluid pressure differential upon diaphragm 23 is now in a direction to return diaphragm 23 to the position of FIG. 2. Freed from engagement with the diaphragm, valve member 36 and pressure plate 45 lare returned to the closed position of FIG. l by the force of spring 38.

The valve is designed to return to a normally closed position when the fluid pressure in chamber 24 is equal to atmospheric. The fluid pressure differential is then zero, and the diaphragm assumes a normal position out of engagement with the pressure plate. The valve member is now subject only to the influence of spring 3S, and the force of the spring is adequate to close the valve. It is thus evident that the valve is opened in response to a fluid pressure differential in one direction on the diaphragm, but the valve is closed by the spring upon disappearance of that differential.

This construction offers several advantages of importance. It permits a very lightweight construction with the result that diaphragm 23 and the pressure plate can be moved with very low pressure differentials and thus they are extremely sensitive to the pressure changes created by the normal inhalation tand exhalation of the used. This sensitivity makes the valve so responsive to the demands of the patient 'that the patient feels substantially no restriction upon his breathing.

The tapered external surface of core 30 in the vicinity of ports 34 and the corresponding taper on the internal bore through valve member 36, creates a valve construction that is highly effective. The taper of the engaging surfaces causes the valve to close securely in a position covering ports 34. Yet, when the valve member is moved away from ports 34, it is free of the core and therefore movement of the pressure plate is not impeded or retarded in any way by frictional drag of the valve member on the core. This facilitates the lightweight construction and improves the sensitivity of the device. Upon closing, the tapered surfaces give a self-centering action to the valve member so that no guides or supporting elements are required to 'guide the valve as it moves between open and closed positions. These characteristics all contribute not only to the simplicity of the device by eliminating as many parts as possible, but also contribute to reliability in operation.

While specific structural details have been shown and described, it should be understood that changes and allterations may be resorted to Without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. In a demand type oxygen valve, the combination comprising: a ho-using having an interior space; a exible diaphragm in said housing forming in cooperation with the housing a chamber, the diaphragm being exposed at one side to atmospheric pressure and yielding to pressure of iiiuid media at opposite sides thereof; a hollow, rigid core extending through Ia housing wall and the diaphragm centrally thereof; means cooperable with said core and said wall to anchor the diaphragm to said wall at the core, said core having a port opening between the ends thereof into said chamber; means providing a passage from said chamber to a user lof the demand type valve; an annular valve member surrounding tand movable relative to the core and movable to a position covering said port in the core to prevent entry of gas into the chamber; means biasing said valve member toward said position covering the port; and means engageable by the diaphragm and movable thereby to move the valve means in opposition to the biasing means to a position uncovering the port in response to fluid pressure on the diaphragm.

2. In a demand type oxygen valve, the combination as in claim l in which the core has a frusto-conical surface at the position of the port and vwhich serves as stop means limiting said valve member to la position closing said port.

3. In a demand type oxygen valve, the combination comprising: a housing having an interior space; a flexible diaphragm in said housing forming in cooperation with the housing a chamber, the diaphragm being exposed at one side to atmospheric pressure and yielding to pressure of fluid media at opposite sides thereof; a hollow, rigid core extending through a housing wall and the diaphragm centrally thereof; means on said co-re for engaging and holding -a portion of said diaphragm against said wall to anchor the diaphragm to the housing at the core, said core having in its side periphery a port opening into said chamber; means providing a passage from said chamber to a user of the demand type valve; an annular valve member surrounding and movable axially relative to the core and movable to a position covering said port in the core to prevent entry of gas into the chamber; means biasing said valve member tow-ard said position covering the port; and a disc mounted on the valve means .and movable therewith, said disc having a central gas-pervious portion that is concave facing the diaphragm, the disc radially outwardly of said central portion being engageable by the diaphragm to be moved thereby in response to pressure of fluid media on the diaphragm to a position in which the valve means uncovers the port and permits gas to enter said chamber.

4. A demand type gas valve unit comprising: a housing; a diaphragm in said housing; said diaphragm having a central portion and a peripheral portion; means fixing said centra-tl portion to a Wall of said housing; means xing said peripheral portion to said housing to form Within the housing a chamber; said diaphragm having between said central and peripheral portions .a flexible portion disposed to move in a circular pattern relative to said wall in response to iiuid pressures on opposite sides thereof; sai-d wall having lan opening exposing one side of said flexible portion to atmospheric pressure; a tubular gas introducing member extended through said wall and said central portion and having a port opening on the side of said introducing member into said chamber; said housing providing a passage for affording communication of a user of the valve unit with said chamber; a valve element surrounding and axially movable relative to said member to open and close said port; means biasing said valve element toward port closing position; stop means embodied in said valve element and said tubular member for limiting movement of said valve element to the position for closing said port; and means in said chamber operable in response to fliuid pressure effected movements of said flexible portion and said diaphragm for moving said valve element to open said port.

5. A demand type gas valve unit comprising: a housing; a diaphragm in said housing; said diaphragm having a central portion; and a peripheral portion; means fixing said central portion to a wall of said housing; means fixing said peripheral portion to said housing to form within the housing a chamber; said diaphragm having between said central and peripheral portions a flexible portion disposed to move in a circular pattern relative to said wall in response -to fluid pressures on opposite sides thereof; said wall having an opening exposing one side of said flexible portion to atmospheric pressure; a gas introducing member extended into said housing and having an outlet port which opens into said chamber; said housing having means forming a passage for affording communication of a user of the valve lunit with said chamber; said member having a tapered exterior surface through which said port extends; a valve element movable on said member to open and close said port and having a surface tapered to conform to and engage said tapered surface of said member so as to wedge against said member when in port closing position; means biasing said valve element toward port closing position; and means in said housing operable in response -to movement of said diaphragm to move said valve element to open said port.

, 6. A demand type gas valve unit comprising: a housing; a diaphragm mounted in said housing to form therewith a chamber; said diaphragm having a first portion and a second portion both fixed against movement lrelative to walls of the housing and dening between said first and l second portions a flexible por-tion disposed to move in opposite directions relative to said walls in response to uid pressures n opposite sides thereof; said housing having an opening in a wall opposite the side of said flexible portion that is disposed exteriorly of said chamber to expose said side to atmospheric pressure; said housing having means providing a passage leading from the exterior of the housing into said chamber; a tubular gas introducing member extending through said wall and said second portion of said diaphragm and having a port opening into said chamber; said member having a tapered exterior surface through which said port extends; a valve element surrounding said member and movable thereon to open and close said port; said valve element having a tapered surface for engaging and wedging said valve element on said member when said valve element closes said port; means biasing said valve element toward port closing position; and means operable to move said valve element to open said port responsive to fluid pressure effected movements of said llexible portion of said diaphragm.

7. In a demand type oxygen valve, the combination comprising: a housing having an interior space; a flexible diaphragm in said housing forming in cooperation with the housing a chamber, the diaphragm being exposed at one side to atmospheric pressure and yielding to pressure of liuid media at opposite sides thereof; means introducing a gas under pressure into the chamber including a port opening into the chamber; means cooperable with said gas introducing mans and a wall of said housing for immovably holding a portion of said diaphragm against said wall around said gas introducing means; means providing a passage from said chamber to a user of the valve; movable valve means moving to a position closing the port to prevent entry of gas into the chamber; means biasing the valve means toward said closed position; and a pressure plate mounted on the valve means and movable therewith, said pressure plate being engageable by the diaphram to be moved thereby to open said port in response to fluid pressure on the diphragm; said diaphragm normally assuming a position out of engagement with said pressure plate and, in response to a fluid pressure differential created by a subatmospheric pressure in said chamber, will move into engagement with the pressure plate to open the valve.

8. In a demand type oxygen valve, the combination comprising: a housing having an interior space; a flexible diaphragm in said housing forming in cooperation with the housing a chamber, the diaphragm being exposed at one side to atmospheric pressure and yielding to pressure of lluid media at opposite sides thereof; means introducing a gas under pressure into the chamber including a port opening into the chamber; means cooperable with said gas introducing means and a wall of said housing for immovably holding a por-tion of said diaphragm against said wall around said gas introducing means; means providing a passage from said chamber t0 a user of the valve; movable valve means moving to a position closing the port to prevent entry of gas into the chamber; means biasing the valve means toward said closed position; and a pressure plate mounted on the valve means and movable therewith, said pressure plate being engageable by the diaphragm to be moved thereby to open said port in response to fluid pressure on the diaphragm; said means for introducing gas into said chamber being a tubular member and having a radially extending slot forming a port in the peripheral surface of the tubular member; said movable valve means including an annular member surrounding and movable axially of said tubular member.

9. In a demand type oxygen Valve, the combination comprising: a housing having an interior space; a flexible diaphragm in said housing forming in cooperation with the housing a chamber, the diaphragm being exposed at one side to atmospheric pressure and yielding to pressure of uid media at opposite sides thereof; a hollow, rigid core extending through a housing wall and the diaphragm centrally thereof; means on said core for engaging and holding -a portion of said diaphragm against said wall to anchor the diaphragm to the housing at the core, said core having in its periphery a port opening into said chamber; means providing a passage from said chamber to a user of the demand type valve; an annular valve member surrounding and movable axially relative to the core and movable While surrounding said core to prevent entry of gas into the chamber; means biasing said valve member toward said position covering the port; and a disc mounted on the valve means and movable therewith, said disc having a central gas-pervious portion that is concave facing the diaphragm, the disc radially outwardly of said central portion being engageable by the diaphragm to be moved thereby in response to pressure of fluid media on the diaphragm to a position in which the valve means uncovers -the port and permits gas to enter said other chamber; said diaphragm normally assuming a position out of engagement with said disc and, in response to a fluid pressure differential created by a subatmospheric pressure in said chamber, will move into engagement with said disc to open the valve.

References Cited by the Examiner UNITED STATES PATENTS 2,746,479 5/1956 Krow l37--505.25 X 2,918,079 12/1959 Krow 137-505.25 X 2,926,683 3/1960 Windsor 137-63 3,020,926 2/l962 Browning 137-508 X FOREIGN PATENTS 590,096 7/ 1947 Great Britain.

WILLIAM F. ODEA, Primary Examiner.

M. CARY NELSON, MARTIN P. SCHWADRON,

Examiners.

J, DEATON, R. GERARD, Assistant Examiners. 

1. IN A DEMAND TYPE OXYGEN VALVE, THE COMBINATION COMPRISING: A HOUSING HAVING AN INTERIOR SPACE; A FLEXIBLE DIAPHRAGM IN SAID HOUSING FORMING IN COOPERATION WITH THE HOUSING A CHAMBER, THE DIAPHRAGM BEING EXPOSED AT ONE SIDE TO ATMOSPHERIC PRESSURE AND YIELDING TO PRESSURE OF FLUID MEDIA AT OPPOSITE SIDES THEREOF; A HOLLOW, RIGID CORE EXTENDING THROUGH A HOUSING WALL AND THE DIAPHRAGM CENTRALLY THEREOF; MEANS COOPERABLE WITH SAID CORE AND SAID WALL TO ANCHOR THE DIAPHRAGM TO SAID WALL AT THE CORE, SAID CORE HAVING A PORT OPENING BETWEEN THE ENDS THEREOF INTO SAID CHAMBER; MEANS PROVIDING A PASSAGE FROM SAID CHAMBER TO A USER OF THE DEMAND TYPE VALVE; AN ANNULAR VALVE MEMBER SURROUNDING AND MOVABLE RELATIVE TO THE CORE AND MOVABLE TO A POSITION COVERING SAID PORT IN THE CORE TO PREVENT ENTRY OF GAS INTO THE CHAMBER; MEANS BIASING SAID VALVE MEMBER TOWARD SAID POSITION COVERING THE PORT; AND MEANS ENGAGEABLE BY THE DIAPHRAGM AND MOVABLE THEREBY TO MOVE THE VALVE MEANS IN OPPOSITION TO THE BIASING MEANS TO A POSITION UNCOVERING THE PORT IN RESPONSE TO FLUID PRESSURE ON THE DIAPHRAGM. 